Cylinder head



May 28, 1946. A, v. D. WILLGOOS CYLINDER HEAD Filed May 22,1942 3SheetsSheet 1 I INVENTOR eflwea'iffl #5259005 May 28, 1946,

A. V. D. WILLGOOS CYLINDER HEAD 3 Sheets-Sheet 2 Filed May 22, 19 42 V wW May28, 1946 A. v. D. WILLGOOS 2,401,210

CYLINDER HEAD Fi'led May 22, 1942 s Sheets-Sheet s INVENTOR Thisinvention relates Patented May 28, 1946 2,401,210 CYLINDER HEAD AndrewWillgoos; West Hartford, Conn., as

sig-nor to United Aircraft Corporation, East Hartford, Conn., acorporation of Delaware Application May '22, 1942, Serial No. 444,032

to improvement in intemal-combustion engines and has particularreference-to an improved cylinder head for an air cooled engine. i

i i An object of the invention resides in the pro vision of fan improvedengine cylinder head of the character indicated which is easy tomanufactureand which can be 1 aforged metal blank.

'Aiurther object resides in the provision of an readily shaped fromterial concentration the inner end of the improved engine'cylinder headof the character indicated which is particularly strong and durable andat the same time of a relatively light weight;

these advantages being accomplished by an imprdved distribution of themetal of which the cylinder headis formed. l I I AIurtherfobject'resides in the provision of an I improved cylinder headof the character indi cated which is symmetrical and'reversible so thaty l v it can be made to operate in either one of two or more operativepositions'on an engine crankcase.

Other objects and advantages will be more particularlypointed outhereinafter or will become apparent as the description proceeds.

In the accompanying drawings, inwhich like reference numeralsare used todesignate similar,

' parts throughoutthere is illustrated a suitablemechanical'embodin'ient for the purpose of disclosing the invention. Thedrawings, however,

I are i'or the purpose of illustration only and are not to be taken aslimiting or restricting the invention since it will be apparent to thoseskilled in the art that various changes in the illustratedembodiment'may be resorted to without in any way exceeding the scope ofthe invention.

In the drawings; i

Fig. 1 isa top plan view of an engine cylinder head constructedaccording to the invention.

Fig. 2 is a sid-elevational head illustrated in Fig. 1. o v

Fig. 3 is a longitudinal sectional view on the line 3-3 of Fig. 1.

Fig. 4 is a sectional view on the line 4-4 of Fig. 1, and

Fig. 5 is a transverse sectional view onthe line 5-5 of Fig. 3.

Referring to the drawings in detail, the cylinder head comprises a bodyportionlo provided with internal threads l2 which are adapted to engagewith external threads provided on a cylinder barrel, not illustrated,the end of which projects into the body portion of the cylinder head.Below the threads l2 the body portion In is extended to provide a, skirtportion H of progressively thinner section which fits over the outer end'of view of the cylinder V construction. Above '4 Claims. (Cl. 123 -171)the cylinder barrel. The absence of any head or portion eliminates anymaofstresses in. the barrel at cylinder head and thu in-.) 3 creases thesafety and durability of the improved the threads l2 the body porform adome-shaped combustion chamber provided with annular receptacles Hiandl8 for the intake andexhaust valve seats and with internally threadedspark plug 1:

ange on this skirt tion In converges to apertures, one of which isindicated at 20.

. Projecting from the body portion! arethef :extensions 22 and 24 whichare made hollow to :3

constitute rocker boxes for the rocker arms of the valve actuatingmechanism. 3

5 These extensions 22 and 24 provide valve guides 26 and 28 which openinto thehollowed-out por- 1 tion of the integral rocker arm boxes. Fromthe o inner end of the valvegulde 26 an exhaust port [f 30 opens throughthe cylinder head between extensions 22 and 24, and an intake port 32leads of extension 24. Extensions 22 vided in the lower tures 36 and 40extends from the lower portion of the extension 22 to the body portionl0. A similar web 42 extends from the undersurface of extension 24 nearaperture 38 to the body portion In of the cylinder head but this web issomewhat deformed to pass around the boss 34.

While a construction has been shown in which; f one of .the valve portsextends to the exterior of the head through the top portion of the head,it is to be understood that, if desiredfboth ports may open through thetop of the head, or both may extend to the sides of the head below therespective rocker boxes, in the manner of the port 34, withoutin any wayexceeding the scope of the invention. i

The fins on both the circular and non-circular portions of the head maybe out (for example) by providing a forging of proper external shape, byapplying a rotary cutter to the forging, and l by so controlling thecutter as to. form separate fins parallel to the ends of 'the head or,if preferred, the fin may be cut inthe form of a continuous helix. Ofcourse, the cutter is controlled" to provide proper predetermined depthsto the fins. Discontinuous fins such as those around the o 1 upper partof the head maybe cut by this same p. 8

method.

The provision of fins in the upper portion of to an annular boss 34provided in the side of the 5 cylinder head just below andslightly toone side and 24 are proa portions thereof with aper- 38 through whichenter the valve push rods.- From aperture 36 a reinforcing Web valveports.

the head is particularly illustrated in Fig. in which the elongated coreportion 46 is shown provided along'each side thereof with continuousfins, as indicated at 48 and 50. This figure shows, in broken lines, thepath of the cutter while forming fins on the non-circular portion of thehead. It will 'be noted that the core portion 46 provides a. relativelythick web 5| between the This core portion, together with the integralweb 40 extending to the side of the head and the relatively thick walledport 32, provide a bridge of relatively tirely across the cylinder headthus adding 'materially to the head strength. v

Both the upper and lower ends of the cylinder head are substantiallyflat, as indicated in Fig. 3, and are parallel to each other. This shapegreatly facilitates the machining of the head blank and also results ina considerable reduction in the height from threads l2 to the uppersurface of the head. The provision of the exhaust valve port 3|] openingthrough the top of the cylinder head between the rocker boxes 22 and 24also is an ad'- vantage in that the hot exhaust gas is kept entirelyaway from the finned portion of the cylinmetal bridge extendingdiametrically across the top of said combustion chamber portion andhaving its longitudinal axis adapted to be positioned in alignmentwithvthe cooling airflow over said head, a pair of elongatedflat toppedvalverocker boxes carried by said bridge at opposite sides of the topthereof, said boxes extending outwardly in opposed relationship fromsaid bridge and havheavy metal extending env der head and there is,therefore, little transfer of heat from the exhaust gases back to thecylinder head.

The improved rocket box and fin arrangement also insures a maximumcooling. effect with a minimum pressure loss in the coolingair flow pastthe cylinder heads since a substantially straight line flow of coolingair across the cylinder and around the valve rocker arm boxes can beobtained. M

It is to be understood limited to the specific embodiment hereinillustrated and described, but may be used in other by the followingclaims:

1. In an aircooled integral cylinder head having a combustion chamberportion, a pair of elongated valve rocker boxes having theirlongitudinal axes aligned and adapted to be positioned in alignment withthe cooling airflow over said head,

said boxes extending oppositely and being positioned in spacedrelationship along the line of their longitudinal axes, a metal bridgeextending across the top of said combustion chamber porthat theinvention is not ing their longitudinal axes aligned and extending inthe directionfof the longitudinal axis of said bridge, a web connectingthe under side of one of said boxes with said combustion chamber at oneside thereof, and a fluid passage extending underneath the other ofsaid-rocker boxes and having a wall constituting a web connecting saidrocker boxxwith the other side of said combustion chamber.

3. A one-piece forged cylinder head for radial aircraft enginescomprising, a dome shaped combustion chamber portion having intake andex haust valve ports symmetrically disposed on opposite sides thereof,valve supporting portions projecting outwardly-at opposite sides of saiddome portion and having valve stem receiving bores therein disposed atacuteangles with respect to the longitudinal axis of the cylinder, avalve rocker box extending laterally, in a direction normal to saidlongitudinal cylinder axis and at an angle with respect to the axis ofthe corresponding valve'stem bore, from each of said valve support- .ingportions adjacent the top of said valve stem tom wall of each of saidboxes.

' ways without departure from its spirit as defined 4. In an aircooledintegral cylinder head having a combustion chamber portion,-a pair ofelongated valve rocker boxes having theirlongitudinal axes aligned andadapted to be positioned in alignment with the cooling'airflow over saidhead, said boxes extending oppositely and being positioned, in spacedrelationship along the line of their longitudinal axes, a metal bridgeextending across the top of said combustion chamber portion between saidboxes and supporting the adjacent ends of said boxesa push rod aperturein -the outer end of each of said boxes and a valve stem aperture intheinner end of each of said boxes, and spaced parallel cooling finssubstantially completely covering saidcombustion chamber portion andsaid bridge, said fins forming cooling air passages adapted to receive acooling airstream flowing in the'direction of the longitudinal axes ofsaid rockerboxes.

D. wnmoos. 1

